四川西部西康群新都桥组碳酸盐岩的锶同位素特征

四川西部松潘—甘孜地区广泛分布一套三叠系黑色砂板岩层系,由于其岩性单调、古生物化石贫乏,给该区地层划分、对比带来极大困难。因此,从锶同位素地层学基本原理出发,对甘孜北部西康群新都桥组中薄层状灰岩样品进行了锶同位素组成测定。结果表明,6件样品的N(87Sr)/N(86Sr)分别为0.708688、0.708659、0.708907、0.708223、0.708341、0.708266,平均为0.708514。表明该地层的碳酸盐岩样品可能遭受了不同程度的成岩蚀变,多数样品的锶同位素组成偏离同时代的全球海水锶同位素组成。     

综合地层学在山东省中生代地层研究中的应用

本文利用综合地层学理论,在研究过程中选用了多门类生物地层学、同位素年龄地层学和火山地层学、生态地层学和岩石地层学及沉积地层学、地震地层学和测井地层学等手段,对鲁北区、鲁西南区、鲁中区和鲁东区中生代地层进行了划分和对比,即把沂沭断裂带以西的坊子组归为中、下侏罗统,三台组归为中侏罗统,分水岭组归为上侏罗统至下白垩统,西洼组归为下白垩统,“王氏组”归为上白垩统;把沂沭断裂带以东的莱阳组主要归为下白垩统中、下部,青山组归为下白垩统上部,王氏组归为上白垩统。     

100Ma来海水的锶同位素组成演化及主要控制因素

讨论了100 Ma以来海水锶同位素比值的变化趋势及控制因素。100~40 Ma期间,海水锶同位素比值有多次升降,总体上变化幅度较小;40 Ma以来,海水锶同位素比值显著增加,并呈现出单调上升的总体特征。100 Ma以来海水锶同位素的变化主要可能与星外物体对地球的撞击作用;全球海平面变化及洋中脊扩张速度的改变;喜马拉雅—青藏高原的隆升;玄武岩喷发和冰川作用因素有关。在各种因素中,喜马拉雅—青藏高原的隆升对40 Ma以来海水锶同位素演化具有最重要的控制作用。喜马拉雅—青藏高原的隆升可能始于40 Ma左右,隆升速度最快的时期在20~15 Ma。     

黄铁矿ReOs法测年在胶东金矿中的应用初探

该次工作为黄铁矿Re-Os法测年在胶东金矿中的首次应用。在大尹格庄金矿中获得了由3件黄铁矿样品组成的(144.8±1.8)Ma等时线年龄,暗示着大尹格庄金矿区可能存在一期晚侏罗世的Au成矿事件。通过对大尹格庄、夏甸、土堆金矿黄铁矿Re-Os同位素年代学的研究,表明黄铁矿的Re-Os同位素特征在胶东金矿中具有一定的复杂性。该文总结了影响黄铁矿Re-Os同位素测年结果的因素,认为在利用该方法进行金矿床定年时,应当将不同期次黄铁矿分别送样,适当拉大采样间距,并尽可能降低实验测试误差,以期获得更精确可靠的年龄。     

矿物微区原位分析与同位素地球化学分析技术在地学中应用

微区原位分析以高空间分辨率和微量分析为核心,结合同位素地球化学的分析技术,满足了地质过程描述中对时间、物质来源、成因环境的识别需求。该文介绍了微区原位分析技术特点及同位素地球化学应用的基本原理。以锆石U-Pb定年为例,回顾U-Pb同位素测年的技术发展,介绍了SHRIMP技术的发展。在此基础上,结合地学研究的需求,提出了未来微区分析技术的发展趋势。     

铜同位素及其在环境污染示踪中的应用进展

近年来,环境问题一直都是社会关注的热点,如大气、土壤和沉积物中的重金属污染问题已成为社会关注的热点。要解决环境重金属污染,关键是要确定其污染源和污染途径,本研究选取了3种典型的污染,即河流污染、冶炼厂地污染及大气颗粒物污染,选择同位素示踪技术作为研究方法,并且以铜作为示踪指标,对铜元素的基本性质,以及铜同位素在地球化学过程中的分馏,不同类型样品的处理、消解以及同位素分离纯化方法,同位素测试技术、示踪技术、端元模型进行了汇总,以及对现已发表的成果中上述3种典型重金属污染的端元(自然输入源和人为输入源),受污染途径、污染程度的研究进行了概括和总结。Cu同位素在环境污染溯源方面尚处于起步阶段,因此还需要进一步研究表生过程中Cu同位素的分馏机理,为认识重金属污染源与汇迁移过程中的机理提供重要的信息。未来的研究中,可进一步运用多种同位素相结合的方法,扩展多元同位素指纹数据库;而且同位素模型是对重金属污染源及污染贡献率进行正确评价的重要研究内容,还需构建新的多同位素多元污染模型来解决更为复杂的污染源。      

碳氮稳定同位素技术在动物食性分析中的应用

<正>自20世纪60年代以来,稳定同位素的应用研究取得突破性进展。近几年,稳定同位素技术已作为一种重要的研究手段应用于生态学领域研究中。已有研究证明,通过测定碳氮稳定同位素自然丰度可以为海洋食物网结构研究提供有益的信息[1]。笔者综述了稳定同位素技术在动物食性研究方面的最新进展,以期为该技术在此方面的应用研究提供参考资料。     

同位素技术在古堆泉岩溶水保护中的应用

岩溶泉水资源是我国北方岩溶区重要的供水水源。查明泉水补给、径流和排泄条件,清晰刻画泉域边界,对合理评估和科学开发岩溶水资源具有重要意义。针对古堆-南梁泉群边界范围不清,补给情况不明的现状,开展了泉域岩溶水文地质条件和岩溶水δD、δ¹⁸O、⁸⁷Sr/⁸⁶Sr分布特征调查分析,采用同位素技术对岩溶水补给径流路径上的水岩相互作用和水力联系进行了系统研究。研究发现,岩溶水中δ¹⁸O数值范围较大,其原因主要是受到了高程效应、热水氧同位素漂移、蒸发浓缩和古封存水混合等作用的影响。岩溶水中δD、δ¹⁸O及⁸⁷Sr/⁸⁶Sr的分布特征,为岩溶地下水水力联系识别提供了有力的佐证：汾阳岭热田成因可能与中生代入侵碳酸盐岩的岩浆岩的水岩作用有关;泉域北部岩溶水开采将袭夺泉域内部岩溶水资源。古堆-南梁泉域岩溶水同位素研究成果可为区域岩溶水资源的管理和保护提供科学依据。     

放射性碳同位素技术在碳质气溶胶源解析中的应用研究进展

碳质气溶胶是大气气溶胶的重要组成部分,能够影响太阳辐射在大气层中的正常传播,与气候变化、空气污染和人类健康等关乎人类可持续发展的重要问题密切相关。大气环境中的碳质气溶胶主要包含有机碳和元素碳,其中有机碳可分为水溶性有机碳和非水溶性有机碳。碳质气溶胶的来源及其形成转化过程是目前大气环境科学领域最为重要的研究方向之一。放射性碳同位素比值(Δ¹⁴C)在碳质气溶胶源解析上具有优势,是目前唯一可以量化化石源和生物源在不同类别碳质组分中贡献大小的手段。在系统总结国内外放射性碳同位素技术在碳质气溶胶源解析上的最新研究进展的基础上,详细阐述了放射性碳同位素比值在碳质气溶胶源解析上的应用原理,深入探究了放射性碳同位素比值在碳质组分中的研究进展,重点分析了单体分子放射性碳同位素分析在碳质气溶胶中的发展和应用。最后,对放射性碳同位素比值与稳定碳同位素比值(δ¹³C)联用,以及单体分子标志物的放射性碳同位素比值研究进行了展望,为碳质气溶胶的来源解析和气溶胶化学过程研究提供参考依据。     

环境同位素在平顶山矿区岩溶地下水污染研究中的应用

通过对平顶山矿区地下水、地表水及大气降水中的氢氧重同位素组成和变化规律分析,结合区域环境水文地质条件及岩溶地下水的一般化学特征,论述岩溶地下水的形成时间、径流途径及径流速度。最后确定岩溶地下水的污染源、污染途径,推断岩溶地下水污染发展的速度。     

Application of transition metal isotope tracers in global change research

High-precision isotope composition determinations using multicollector, magnetic-sector inductively coupled plasma mass spectrometry (MC-ICPMS) have recently revealed that some transition metal isotopes such as those of Mo, Fe, Cu, Zn etc. can be used as biogeochemical tracers in global change research.The Mo isotope system may be useful in paleoredox investigations indicating that δ^97 ^95Mo in seawater may co-vary with changes in the relative proportions of anoxic and oxic sedimentation in the ocean, and that this variation may be recorded in δ^97 ^95Mo of anoxic sediments. The Mo continental flux into the oceans and the global Mo isotope budget can be estimated from δ^97 ^95M0 values. The Fe isotope composition in seawater is an important issue because Fe plays a controlling role in biological productivity in the oceans and its abundance in seawater may have substantial effect on climate changes. Iron isotope fractionations could result from bio- and abio-processes and have about 0.1% variation ( δ^56 ^54Fe), so Fe isotopes considered alone cannot be used to distinguish the products of abiotic and biotic Fe processing in geological records. Cu and Zn isotopes are also used as biogeochemical tracers, but the researches are relatively less. This review mainly focuses on the methods for preparation, purification and determination of new isotope tracer samples, and on isotope applications in marine environmental changes.     

Application of stable isotope techniques in studies of carbon and nitrogen biogeochemical cycles of ecosystem

Stable isotope techniques have been proved useful as tools for studying the carbon (C) and nitrogen (N) biogeochemical cycles of ecosystem. This paper firstly introduced the basic principles and the distribution characteristics of stable isotope, then reviewed the recent advances and applications of stable isotope in the C and N biogeochemical cycles of ecosystem. By applying the 13 C natural abundance technique, ecologists are able to understand the photosynthetic path and CO 2 fixation of plants, the CO 2 exchange and C balance status of ecosystem, the composition, distribution and turnover of soil organic C and the sources of organic matter in food webs, while by using the 13 C labeled technique, the effects of elevated CO 2 on the C processes of ecosystem and the sources and fate of organic matter in ecosystem can be revealed in detail. Differently, by applying the 15 N natural abundance technique, ecologists are able to analyze the biological N 2 -fixation, the N sources of ecosystem, the N transformation processes of ecosystem and the N trophic status in food webs, while by using the 15 N labeled technique, the sources, transformation and fate of N in ecosystem and the effects of N input on the ecosystem can be investigated in depth. The applications of both C and N isotope natural abundance and labeled techniques, combined with the elemental, other isotope ( 34 S) and molecular biomarker information, will be more propitious to the investigation of C and N cycle mechanisms. Finally, this paper concluded the problems existed in current researches, and put forward the perspective of stable isotope techniques in the studies on C and N biogeochemical cycles of ecosystem in the future.     

Response of microbial community to petroleum stress and phosphate dosage in sediments of Jiaozhou Bay,China

The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sediment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollution and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel electrophoresis (DGGE) techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually enhanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and consequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation.     

Response of Microbial Community to Petroleum Stress and Phosphate Dosage in Sediments of Jiaozhou Bay,China

The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sedi- ment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollu-tion and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel elec- trophoresis （DGGE） techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually en-hanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and con- sequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation.     

APPLICATION OF REMOTE SENSING AND FUZZY MATH TO STUDY OF SUSPENDED SEDIMENTS DIFFUSION NEAR THE HUANGHE RIVER DELTA

Sediment grain size parameters and the percent of sand and clay near the Huanghe River Delta are used to estimate the Huanghe Riser load diffusion with fuzzy analysis. The results are confirmed by field investigation and the landform changes of the river estuary and sediment diffusive pattern indicated by Landsat MSS, TM images.     

改进型回溯法在高校排课中的应用

综合回溯算法的特点和实际应用中的具体情况，提出改进型回溯法，即广度优先回溯算法Broad FirstBackdate(BFB)；并遵循高校排课的基本原则，利用队列、堆栈、课程相关等概念，给出了一个BFB的具体实现，对基于高校排课中的冲突进行处理，它是大学课表编排系统University Timetable Arranging(UTAS)使用的关键方法之一。     

虚拟站点在黑河流域降水模拟中的应用

降水作为气候系统的关键因素,也是影响区域植被生长以及生态变化规律的重要因子。本文针对黑河流域气象站点分布稀疏情况,采用信息熵及半变异函数理论构建该流域虚拟气象站点,并结合部分已有站点对整个流域降水进行插值模拟。信息熵可以计算每个站点降水值所包含的信息,通过联合熵以及条件熵来依次选取所含信息量多的站点,同时结合半变异函数模型来观察各站点之间的空间相关性,以此构建最优站点数据集。利用1991-2003年该流域15个气象台站的年平均降水量作为基础数据,考虑高程、坡度、坡向对降水的影响,对降水进行相关性分析,建立回归方程反演虚拟站点降水值。最后,采用协同克里金（Co-Kriging）与具有漂移的克里金（KED）方法对该流域进行插值,对比插值精度。结果表明,增加虚拟站点有效提高了降水插值精度,在该情况下使用KED方法插值结果与观测值最接近。